Window sealant (5)
I believe the answer is:
putty
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">window sealant</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for putty that I've seen before include "Malleable form of glas holder" , "Whiting and linseed oil paste" , "Window glass sealant" , "Glazier's paste" , "Glass pane securer" .)